Polymarket listed event contracts on Major League Baseball games for the 2026 season, including moneyline, spread, totals, props, and futures markets. The contracts are live for a Chicago White Sox vs. Chicago Cubs game scheduled for August 18, 2026. Separately, Major League Pickleball used Polymarket to generate odds for its playoff quarterfinal matches. No specific odds numbers or volume data were disclosed. Both listings expand Polymarket's sports offerings without addressing the platform's recurring depth problem, which prior coverage has documented across multiple baseball contracts.

This expansion adds futures and props to Polymarket's baseball menu, but the platform's sports liquidity problem remains unresolved. Prior coverage has documented violent price swings across Reds, Tigers, Pirates, and Rays contracts, with spreads widening 20-70 points on thin volume. Retail traders entering near the midpoint absorb mark-to-market pain when books gap. Institutional market makers watching these contracts cannot verify two-sided depth, so they stay away. Kalshi faces parallel opacity in its own baseball markets, which gives neither platform a clear credibility edge. The listing itself is not the story; whether Polymarket fixes market-making depth before volume builds is. Without that fix, each new sport or prop deepens the fan-engagement-with-margin-calls cycle.